算术加法（+）不NG绑定工作 [英] Arithmetic addition (+) is not working in ng-bind

问题描述

有是具有对象

objData.pendingCount = '2',objData.refundCount = '1',objData.saleCount = 43;

我执行

<td ng-bind="(objData.pendingCount / objData.saleCount * 100).toFixed(2)"></td>

这是工作正常，但是当我做

this is working fine but when I do

<td ng-bind="(objData.pendingCount +objData.refundCount)/ objData.saleCount * 100).toFixed(2)"></td>

下面+不执行算术调度研究，而这是concating。我怎样才能做到这一点？

Here + is not performing arithmetic opration rather it is concating. How can I achieve this ?

推荐答案

我认为这些价值来自于某种形式的文本框（通过NG-模型）。如果是这样，解决这一问题最简单的方法是设置一个他们键入='号'和角度会采取其他的事情！

I assume that these values come from a text box of some sort (via ng-model). If so, the easiest way to fix this would be to set a type='number' on them and angular will take care of the rest!

<input ng-model="objData.pendingCount" type="number" />
...

另一种方法是简单地preFIX +强制数字转换，像这样

The alternative is to simply prefix + to force a number conversion, like so

<span ng-bind="((+objData.pendingCount + +objData.refundCount)/ objData.saleCount * 100).toFixed(2)"></span>

---

为什么不能使用数字（...），以使字符串一个数字在角前pression

使用编号字符串转换为数字不会直接因为（从的 https://docs.angularjs.org/guide/ex$p$pssion ）

Using Number to convert the string to a number will not work directly because (from https://docs.angularjs.org/guide/expression)

环境：JavaScript的前pressions是针对全球评估
  窗口。在棱角分明，前pressions是针对一个评估范围的对象。

Context: JavaScript expressions are evaluated against the global window. In Angular, expressions are evaluated against a scope object.

所以，如果你需要使用编号，你可以这样做

So if you need to use Number you can do something like

$scope.Number = $window.Number;

在您的控制器在你的前pression使用它之前。这同样适用于全球其他的窗口属性。

in your controller before you use it in your expression. The same goes for other global window properties.

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